This invention relates to a hollow filament co-spun with a core within the hollow filament and spinnerets for co-spinning such filaments.
Hollow-fiber membrane bioreactors are known and have utility in the production of materials from suspended or immobilized enzymes or cell cultures. Cells or enzymes are located within or outside of the hollow fibers with reaction substrates being supplied to the cells or enzymes while desired products are removed. Due to the compact proportions of a bioreactor, known manual methods of manufacturing such membranes are costly and time consuming, particularly when dual hollow filaments of extended length and fine diameter are involved.
Hollow-within-hollow fibers have been described in U.S. patent application Ser. No. 879,571 of common assignee filed June 27, 1986, now U.S. Pat. No. 4,743,894. In these hollow-within-hollow fibers, the inner surface of the outer filament and the peripheral surface of the inner filament can touch along their length to a significant degree. This contact can decrease the effective area of filament surface exposed to fluids or materials located in the space between the filament.